The invention is related to the field of multiple-position modular connectors used in digital data transmission such as transmission over unshielded twisted pair (UTP) cables.
Data communications devices make common use of UTP cable for high-speed digital data transmission. Data is transmitted in a differential fashion over each of one or more twisted pairs of a multiple-pair cable, such as four-pair Category 5 or Category 6 UTP cable. The mechanical and electrical interface between the cable and a device is often made via a multiple-position modular connector, commonly referred to as an “RJ45” connector for example. The connector includes a female jack with multiple conductors (e.g., 8) extending into a cavity, and a corresponding male plug with conductive contacts that made with the conductors of the jack when the plug is inserted into the cavity. A lever or similar mechanical lock holds the plug securely in place. Typically the jack is affixed to the data communications device (e.g., a computer or network switch) and the plug is affixed at an end of a cable which is carrying the data signals between the device and other equipment.
Over time, various advances have made it possible to send data over UTP and STP (shielded twisted pair) cables at increasingly high rates. Currently there is a specification for sending data at 10 Gb/s over four UTP pairs and four STP pairs, which corresponds to a signaling rate of 2.5 Gb/s on each pair. The communications links are susceptible to high-frequency noise, such as from wireless telephones, cell phones, etc. In these systems the noise margins for proper operation are very small, on the order of tens of millivolts. Generally, the links employ suitable circuitry and mechanical configuration to provide proper high-frequency operation in the presence of such noise. Although the RJ-45 style modular connector was not created with such high-frequency operation in mind, and therefore may unduly contribute to noise in a high-data-rate communications link, it is still specified for use even on such links for a variety of reasons.